Laminated materials for covering surfaces of buildings



Dec. 22, 1970 c. "r. BENTON LAMINATED MATERIALS FOR COVERING SU RFACESOF BUILDINGS Filed Se t; 14, 1967 2 Sheets-Sheet 1 V/V 4/ ///l I,

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LAMINATED MATERIALS FUR COVERING SURFACES 0F BUILDINGS Filed Sept. 14,1967 2 Sheets-Shoot 2 11. .8 157 Ifi 4%; J/WEA/YQR United States Patent3,549,471 LAMINATED MATERIALS FOR COVERING SURFACES OF BUILDINGS ClydeT. Denton, Los Angeles, Calif., assignor to Resilient ServicesIncorporated, Los Angeles, Calif., 21 corporation of California FiledSept. 14, 1967, Ser. No. 667,705 Int. Cl. B32b 3/00 US. Cl. 161-86Claims ABSTRACT OF THE DISCLOSURE An underlayer for floor or wallcoverings is prepared by permanently bonding upper and lower continuouslayers, typically of impregnated muslin, to a membrane that is slottedto accommodate dimensional changes due to moisture, heat, cold and thelike, the cover layers preventing filling of the slots with adhesiveduring application.

Tile units are made up with such a composite underlayer on one face.After laying, such tiles are unified by an overcoat of fully compatiblematerial that fills cracks between tiles.

Base and border assemblies utilize a similar underlayer, and may includea flexibly joined tack bar for securing a carpet. Flexible covestructures may be lifted to insert a carpet edge. Improved fit betweenthe base and border assembly and the field covering is secured by meansof tapered shim stock that extends from the border under the fieldcovering.

Fit between sections of base is facilitated by an overlap with the frontflange longer than the back flange.

This invention has to do with materials and methods for coveringsurfaces of buildings. The invention is concerned particularly, but notexclusively, with covering floors and the adjoining base areas of walls.

A primary object of the invention is to obtain smooth and reliablebonding between the building surfaces and the covering materials despiteunevenness of the building surfaces and despite expansion andcontraction of any portion of the covering materials due to dampness,heat, cold and similar causes.

An important aspect of the invention relates to the accommodation of theexpansion and contraction of the protective membrane that is customarilyinstalled between the building surface and the main elements of thecovering. Such a membrane is often formed of felt or other fibrousmaterial that tends to swell in presence of moisture or heat. Normalimpregnation of such a membrane with water resistant materials such asasphalt, for example, does not entirely eliminate the variable diffusionof moisture when the covering is laid on surfaces such as concrete, forexample. I have previously described a method of preventing theresulting expansion and contraction of the membrane from producingbuckling of the floor covering by providing the membrane with aplurality of mutually spaced, multi-directional slots that accommodatelateral movements of local areas of the membrane. My Pat. 2,556,071describes a particularly effective slot structure for that purpose. Thepresent invention provides more convenient and economical materials andmethods for utilizing such slotted membranes, leading to greater ease ofinstallation and longer life of the resulting covering assemblies.

One aspect of this invention provides a laminated subassembly comprisinga slotted membrane with upper and lower layers of muslin or likematerial so bonded to its opposite faces that the membrane slots remainreliably hollow and unfilled by the bonding agent. Such a sub- PatentedDec. 22, 1970 'ice assembly can be applied to a building surface, and acovering layer then adhered to its outer face, by rapid and economicalconventional procedures, since precautions are not required to preventfilling of the membrane slots with adhesive.

A further aspect of the invention provides tile units of interfittinggeometrical shape having a membrane of the described type integratedwith them, preferably in a manner that provides overlap between adjacentunits. Such tile units are conveniently assembled to form an effectivelycontinuous covering for a fioor or other building surface with theadditional advantage of accommodating expansion and contraction that maybe caused by moisture, heat, cold and the like.

The invention further provides improved types of integrated base andborder for a floor area, which are economical to apply, adhere reliablyto the building surfaces and provide accurate and reliable fit andalinement with the field covering. Such base and border assemblies maybe designed to receive any desired type of field covering, including, inparticular, individual tile units, vinyl carpet materials, andconventional carpets, as well as field coverings produced by wet pouringon the job.

In laying a carpet, for example, in conventional practice the edgeportion of the carpet is ordinarily secured by engaging hook formationsof a tack strip which is fastened directly to the floor. A plain basestrip may be cemented to the wall either before or after the carpet isinstalled, but generally leaves an unsightly and unsanitary crevice.That difficulty may be largely overcome by employing a cove base withcurved lower portion adapted to overlie the edge portion of the carpet.However, if such a base is applied before installation of the carpet,the carpet edge must be tucked under the cove base, tending to pry thebase away from the wall; while later application of the cove base risksdamaging the carpet with adhesive.

One aspect of the present invention overcomes those difiiculties byproviding a combined base strip and tack bar which is readily installedas a single operation, permits convenient placement or removal of thecarpet, and provides a stronger and more reliable fastening than wasnormally obtainable with previously available structures.

The invention further provides improved base and border assemblies withintegrated coving. One form of such assembly permits particularlyconvenient and secure installation of carpet floor covering in the fieldarea. Other forms are particularly adapted for field covering employingtile units, and can be cut after installation to fit varying fielddimensions.

A further important feature of the invention provides a taperedshim-like flange that extends along the fioor from the edge of theborder and underlies the periphery of the field covering material,whatever the nature of the latter. Such shim structure insures level fitbetween the border and field despite irregularities of the floorsurface, greatly facilitating installation and improving the quality anddurability of the job.

A further aspect of the invention provides an especially smooth anduniform and essentially unitary surface particularly well suited forfloors. That is accomplished by applying over the main floor covering acoat of liquid polymerizable resin, preferably of the same type that isembodied in the main floor covering, and allowing it to polymerize inposition. Such an overlayer is especially useful in connection with afioor covering of assembled units, such as the tile units of the presentinvention, for example. When so applied, the overlayer is preferablycaused to penetrate the cracks between the covering units, essentiallyunifying them into a continuous, completely seamless and waterimpervious covering.

A full understanding of the invention, and of its further objects andadvantages, will be had from the following description of certainillustrative manners in which it can be carried out. The particulars ofthat description, as of the accompanying drawings which form a part ofit, are intended only as illustration, and not as a limitation upon thescope of the invention, which is defined in the appended claims.

In the drawings.

FIG. 1 is a schematic perspective illustrating one aspect of theinvention;

FIG. 2 is a schematic perspective representing a tile unit in accordancewith the invention;

FIG. 3 is a section at enlarged scale, taken as indicated by the line3-3 of FIG. 2 and representing a modification;

FIG. 4 is a fragmentary section at further enlarged scale, representinga completed floor covering utilizing tile units in accordance with theinvention;

FIG. 5 is a schematic perspective representing a base structure inaccordance with the invention;

FIG. 6 is a fragmentary section illustrating typical installation of amodified base structure;

FIG. 7 is a fragmentary section representing a further,

modified base structure;

FIG. 8 is a section illustrating typical installation of the basestructure of FIG. 7;

FIG. 9 is a schematic perspective representing a base strip and tack barassembly in accordance with the invention;

FIG. 10 is a section at enlarged scale on line 10-10 of FIG. 9; and

FIG. 11 is a schematic perspective representing a modified base stripand tack bar assembly.

FIG. 1 represents schematically one embodiment of the present invention,comprising an integrated sandwich structure of three layers. The middlelayer 32 is a flexible membrane, typically of fibrous material such asfelt, for example, made water-resistant by saturation with a non-fibrouswater-impervious material such as a polymerized epoxy or vinyl resinhaving suitable flexibility. For some purposes membrane 30 may comprisea synthetic resinous material without any fibrous component. Membrane 30is pierced by a plurality of narrow, mutually spaced, vari-directionalslots 34, which may be grouped to form the zig-zag patterns indicated at36.

The upper and lower layers 38 and 39 of assembly 30 comprise continuoussheet material, typically conventional muslin impregnated withpolymerized epoxy or vinyl resin, which is firmly bonded to therespective faces of membrane 32. That bond is typically produced bywetting the opposing surfaces of the two muslin layers 38 and 39 withadhesive in the form of liquid polymerizable resin of the same type asthat impregnating the muslin and membrane 32, rolling the three layerstogether, and allowing polymerization of the liquid to essentiallyintegrate the three layers into a single unified sheet. The amount ofsuch liquid applied is carefully limited to prevent filling the slots 34of the membrane, so that after integration the slots form sealed hollowchambers unfilled by resin or any other adhesive material that is used.The membrane assembly of FIG. 1 may be fabricated and sold in largesheets, or preferably as long strips supplied in rolls, as indicated at35.

Slots 34 are made narrow enough to insure effectively continuous supportfor the covering sheets of muslin or the like at 38 and 39. However,even very narrow slots, particularly when formed in zig-zag patterns asillustrated, are capable of accommodating any expansion or contractionof the flexible membrane that normally results from diffusion ofmoisture or from heat, cold or other causes.

The present membrane assembly 30 has the great advantage that it can beadhered to a wall or floor surface as an underlayer for any desiredcovering material Without requiring care during such assembly to avoidfilling the slots 34 with adhesive. The muslin layers 38 and 39 protectthe slots and also provide a good bond with any normally used adhesives,which can therefore be handled in conventional manner without specialprecautions.

FIGS. 2 and 3 illustrate schematically a tile unit 40 in accordance withthe present invention. The numeral 42 designates a tile element of anydesired kind, typically a conventional resilient covering material suchas polymerized resin, or a vinyl carpet, for example. Element 42 is ofsuch geometrical shape that tile elements can be assembled together toform a continuous covering layer for a floor or other building surface.That shape may, for example, be rectangular, triangular, diamond-shapedor hexagonal, being shown rectangular for illustration. Tile element 42is firmly bonded to a support assembly 44 comprising a membrane layer 45sandwiched between upper and lower protective layers 46 and 47. Membranelayer 45 is like membrane 32 already described in connection with FIG.1, and is preferably similarly slotted. Layers 46 and 47 are typicallyof muslin, impregnated as described in connection with layers 37 and 38of FIG. 1. Support assembly 44 is typically of the same shape and sizeas tile element 42, but is offset diagonally with respect to the latterto provide flanges 50 and 51 adapted to overlap between adjacent tileunits on assembly. The upper faces of the support flanges 50 and thelower faces of the tile element flanges 51 are preferably provided withpressure sensitive adhesive to facilitate binding the adjacent tileunits togther on assembly. Such adhesive is indicated in FIG. 3 ascomprising an adhesive layer 52 and a smooth protective strip 53 that ispeelable from layer 52 in conventional manner just prior to assembly ofthe units.

In the manufacture of tile units of the type shown in FIGS. 2 and 3, itis convenient to prepare the support assembly 44 initially in the formof large sheets or rolls of sandwich structure, as described inconnection with FIG. 1, and to cut support units of the desired size andshape from that sheet material for assembly with the tile units 42. Thelatter may be cut from sheet material, cast to shape from polymerizablematerial, or formed in any other suitable manner. The tile unit andsupport assembly may be joined with any suitable adhesive material,preferably resin cement of the same type employed in base 44. When thebuilding surface to be covered is subject to heavy wear it is oftendesirable to employ a tile 42 of composite structure, as indicated inFIG. 3, comprising a main layer 48 of conventional resilient coveringmaterial with a surface layer 49 of polymerized epoxy or vinyl resin,which may be precast and combined with the main layer by means of a filmof polymerizable liquid resin.

The tile units of FIGS. 2 and 3 can be installed on the building surfaceto be covered by means of any suitable adhesive, the lower layer 47providing a satisfactory tooth for bonding with the adhesive. Afterplacing of each unit, the pressure sensitive adhesive layer 52 on theflange 50 is exposed by removal of cover layer 53. Before placing theadjoining tile unit, the pressure sensitive adhesive layer on the lowerface of flange 51 is similarly exposed. Upon contact of the two exposedadhesive layers, they form a strong bond, effectively unifying theseveral units. After all the tile units have been placed, the surface ispreferably coated with a layer of liquid polymerizable resin of the sametype that was employed in fabricating the tile units. That layer isshown illustratively at 56 in FIG. 4. It should be thick enough toprovide ample liquid to penetrate any remaining crevices between tileunits, as indicated at 58 and 58a. Upon polymerization of that liquid,there results continuous, impermeable and highly integrated coveringstructure.

FIG. 5 represents a coved base structure 60 which is provided with ashim stock extension in accordance with the present invention. The basestrip 62 is typically molded of a Water impervious, slightly flexiblematerial such as rubber, linoleum, a conventional polymerized epoxy orvinyl resin, or similar material. It has a smooth front face curvingback at the top to a sharp top edge 61 that is resiliently prestressedin a rearward direction to fit tightly against a wall surface andaccommodate slight irregularities in that surface. Conventional grooves61a are provided in the rear face of the base strip near the top edge totrap excess adhesive. The base strip is provided with the coved region63 terminating in the short toe region 64 with edge 65. Beyond the toeedge 65 the shim stock 66 extends adjacent the floor surface. Thethickness of shim stock 66 where it first emerges from base edge 65 isonly sufficient to give it the required strength, and that thicknesstapers gradually essentially to zero at the shim edge 67. The shim stockis preferably integral with the backing layer 68, which coversessentially the entire contact face of base 62 and may be ofconventional type. If backing layer 68 is muslin, for example,impregnated with water impervious material such as polymerized resin,the main body of shim stock 66 may comprise an extension of thatimpregnated muslin. The tapered edge portion of the shim stock can thenbe formed of polymerized resin of the same type as that impregnatingthei, muslin, of which it constitutes an integral extension.

FIG. 6 illustrates typical installation of the base assembly of FIG. atthe corner between a typical building floor 70 and wall 72, and furtherillustrates modified toe structure. The floor surface is shown with alocal depression at 73, exaggerated for clarity of illustration, thenormal floor level being represented by the dashed line 74. The baseassembly is installed with conventional adhesive and/or fillermaterials, represented by the numeral 76. That adhesive and/or fillerfills the corner area 7611 back of the cove region 64 of the base andalso fills floor depression 73. Aside from those regions, the adhesivelayer is, of course, very thin, but is exaggerated in the figure forclarity of illustration.

As used herein, the expression field is intended to include floors,walls and other interior surfaces of buildings.

The field area of the floor is covered by a typical floor covering,represented at 78. That covering o'verlies shim stock 66 of the baseassembly, and abuts base edge 65. Due to the inherent stiffness of base60, caused in large part by the curve of the cove region, the toe areaof the base tends to bridge the floor depression 73, as illustrated. Onthe other hand, the edge portion of the field covering, if it were notsupported by the shim stock, would sag into floor depression 73. Thatwould cause misalinement between the field and the toe region of thebase, exposing an unsightly and unsanitary corner at edge 65. However,with shim stock 66, as illustrated, the edge of the field covering isreliably held in proper alinement with the base toe despiteirregularities in the floor surface.

Field covering 78 is shown in FIG. 6 as a carpet 77 laid on the paddinglayer 79. The toe of base 60 is recessed to form the lower edge face65a, of suitable height to about padding layer 79, and the upper edgefaces 65b which receives the edge of the carpet proper. The carpet isanchored to the shelf 80 of base 60 by means of the pins 81, setobliquely in the base at the time of manufacture. The metal trim strip82 may be added if desired, and is typically fastened to shelf 80 by thescrews 83, covering the pin ends and retaining the carpet more securelyon the pins.

The base structure shown in FIG. 6 is also well adapted for receivingfield covering material that is wet poured on the job. Shelf 80 providesa convenient guide surface for the major fill, which adjoins edge 65a,while the topping layer of the fill covers the shelf and adjoins edge65b. The resulting ship-lap effect insures accurate and desrablealinement of the field and base surfaces. Pins 81 may be omitted, or mayprovide further reinforcement of the joint between field and base.

FIG. 7 represents a modified base structure in which a slotted membrane84 has been integrated. Such a membrane may be included also in thestructures of FIGS. 5

and 6. As illustratively shown in FIG. 7, membrane 84 is adhereddirectly to the back surface of base 62, typically by employing asadhesive a liquid polymerizable material of the same type of which thebase is formed. Base strip 62 is preferably recessed to receive themembrane, as indicated at 86, with the membrane limited to the base andcove portions of the base strip, where the accommodation of expansionand contraction is most often required. Membrane 84 is covered by asuitable protective and bonding layer 68, typically of muslin or thelike. That layer preferably leads directly into the shim stock extension66 in the manner already described in connection with FIG. 5. Incementing layer 68 to membrane 84, as in assembling the membrane to thebase strip, care is taken to avoid filling the membrane slots 85 withadhesive, as already described.

A further aspect of the invention relates to a base assembly structurethat is particularly adapted for use with a field covering that has aninherent dimensional limitation, so that the toe region of the base mustconform to the field dimension. For that purpose the toe region 88.ofthe base strip is formed of relatively flexible material. Moreover,though directly overlying shim stock 66, the base toe region isseparable from the shim stock for an appreciable distance back from thetoe edge, as indicated in FIG. 7 by the dashed lines 88a. The toe edgeis preferably rounded, as indicated at 89. That manner of constructionpermits the following highly convenient and effective procedure forinstallation. The base assembly is first secured in place essentially inconventional manner, typically by application of suitable adhesivebetween muslin layer 68 and the wall surface and between shim stock 66and the floor surface. During that installation, toe region 88 of thebase strip is allowed to overlie the shim stock directly, tending tohold the latter accurately fiat so that any irregularities in the floorsurface will be filled by adhesive, essentially as illustrated in FIG.6-. The rounded toe edge 89 tends to prevent damage to the base aftersuch installation and before installation of the field coveringmaterial. For installation of the field, toe region 88 of the base stripis lifted, as in FIG. 8, permitting the field covering 90 to be insertedunder it but above shim stock 66. The field covering edge 92 istherefore supported on an accurately flat surface, independently ofminor variations of the floor surface. The exact position of the fieldedge 92 is assumed to be determined by the field structure. For example,the field covering may be conventional resilient sheet material having apattern that limits the edge position; or the field may comprise tileunits that are preferably not broken at the edge. Such a variableposition of edge 92 is accommodated, after installation of the fieldcovering as in FIG. 8, by cutting the toe of the base to fit the laidfield. That may conveniently be done by scribing the upper face of thebase strip at 94 with a conventional instrument guided by edge 92 andthen hand cutting the base at 95 to the scribed line. Toe region 88 isthen cemented down to shim stock 66, giving an accurate fit with thefield covering as indicated at '96. Adhesive layers are omitted in FIG.8 for clarity of illustration.

A combined base strip and tack bar in accordance with a further aspectof the invention is represented at in FIG. 9. The base strip proper isindicated at with the main body 111 of molded water-impervious material,the membrane 112 slotted at 113 (see FIG. 11), and the protective andmounting layer of muslin or the like 114, formed and structurallyintegrated in a manner similar to that described in connection with FIG.7, for example. Base strip 100 is preferably formed with readwardlyprestressed top edge 116 and adhesive retaining channels 118. The bottomedge of the base strip is not coved, but is beveled as indicated at 120to permit a snug fit to the floor and wall surfaces despite roughness orirregularity of the corner between them. Backing layer 114 extendsforwardly from the bottom edge of the base strip, as shown at 122.

The tack bar 130 may be of conventional wood construction or othersuitable material with prongs 134 extending obliquely from its upperface. The tack bar has its lower surface firmly bonded to the muslinextension 122 in parallel relation to the base strip but spacedtherefrom by a narrow gap indicated at 132. The free strip of muslin at123 between the tack bar and base strip forms a flexible hinge structurethat accommodates slight irregularities in the floor and wall surfaces,and permits folding of the assembly for more convenient storage andhandling prior to use.

The combined base strip and tack bar is installed prior to laying thecarpet or similar floor covering. Base strip 110 is adhered to the wallsurface by any suitable adhesive, which may be applied in conventionalmanner without danger of filling the slots 113 of membrane 112. Tack bar130 may also be adhered to the floor, though for some installations thetack bar is retained in position sufiiciently firmly by muslin hinge123. Conventional carpet padding is typically laid on the floor up tothe tack bar, and the carpet installed in normal manner, firmly abuttingthe front face of base strip 110. The carpet edge may be bent downwardinto the channel 132 between the tack bar and base, giving a neat andfinished appearance.

FIGS. 9 and 10 illustrate further aspect of the invention, wherebyimproved fit is obtained at the vertical junctions 140 between adjacentsections of base strip. The ends of the sections are flanged, as shownbest in FIG. 10, in a manner providing an overlap at the joint. The flatcontact faces at 142 tend to define the front faces of both sections,permanently retaining them in accurate and smooth alinement despiteslight wall irregularities. Furthermore, front flange 143 is madeappreciably longer than rear flange 144. Under normal installation, withcompletely true wall and floor surfaces, that merely produces a verticalopen channel 146 at the back of the base strip, causing no difficulty.On the other hand, unevenness in the floor surface sometimes requiresthat adjoining sections of base depart slightly from strict parallelismin a vertical plane. With the present construction such departure fromparallelism can be accommodated by suitable slightly oblique trimmingsof the end face 148 of front flange 143 of one base section. Rear flange144 of the adjacent base section does not require correspondingtrimming, except in the rare case in which more material must be removedthan the width of rear channel 146.

The structure shown in FIG. 11 differs from that of FIG. 9 mainly inproviding a cove strip 150, which is mounted on base strip 110a at 152and is preferably essentially integral therewith. Cove strip 150 isjoined to the base strip at an area 152 of the latter intermediate itsupper and lower edges, curving downward and outward therefrom in atangential manner. The free edge 154 of cove strip 150 is tapered andcurved downwardly in a manner to abut directly against the upper surfaceof an installed carpet or other field covering material. A typicalcarpet is shown at 160, with underlying carpet pad at 166. The covestrip is constructed in such a way that it is resiliently flexible withrespect to transverse bending, so that the free edge 154 can be liftedan inch or two above the carpet surface, as indicated in dot-dash linesat 150a, and will return resiliently when released to the position shownin solid lines. Such resilience is obtainable by selection of a suitabletype of polymerized resin material, typically different in compositionfrom the main body of base strip 110a, but compatible with it andcapable of forming an eflectively unitary structure. However, I preferto enhance the resilience and strength of cove strip 150 by embedding init a metallic resilient core 156. That core is typically of relativelythin sheet material, as indicated at 157, and preferably has deeplyserrated edges, as indicated at 158, giving the core a Zig-Zag patternas seen in plan. With that composite. structure of resilient metal coreembedded in a homogeneous body of suitable polymerized resin, the covestrip may be light in weight, effectively flexible to facilitateinstallation of the carpet, and yet strongly resilient to insure a firmand tight contact with the carpet after installation.

A combination base strip and tack bar with cove strip as shown in FIG.11 is typically installed as already described with reference to FIGS. 9and 10. Carpet pad 166 is then laid on the floor, and the carpet isinstalled over it. The carpet edge is preferably cut somewhat oversize.By lifting the cove strip as indicated at 150a, the carpet edge isreadily inserted beneath it and secured to the prongs 134 of the tackbar. The surplus carpet is folded back, as shown at 162, within thechamber 164 of generally triangular section formed by the cove strip,tack bar and base strip. The resilience of that folded carpet tends toenlarge the chamber, thus pressing the lower part of the base striptoward the wall, supporting the intermediate portion of the cove strip,and retaining the carpet securely on prongs 134.

I claim:

1. An integrated assembly applicable as a unit to a surface of abuilding as at least a partial covering therefor, comprising incombination a membrane of material that tends to swell when exposed toheat or dampness, pierced by a plurality of narrow, mutually spaced,variously directed slots to accommodate lateral movement of localmembrane areas relative to each other,

a substantially dimensionally stable, water impervious layer adheredpermanently to the upper face of the membrane,

and a muslin sealing layer impregnated with water impervious syntheticresinous material to form a continuous sheet, adhered permanently to theunder face of said membrane and adapted to be bonded to a buildingsurface by a conventional adhesive,

the membrane slots forming hollow chambers unfilled by bonding materialand sealed by said layers.

2. An assembly as defined in claim 1 and in which said dimensionallystable layer comprises muslin impregnated with substantially the samesynthetic resinous material as that impregnating the first said muslinlayer.

3. An assembly as defined in claim 1 and in which said dimensionallystable layer comprises an interlayer of muslin impregnated with waterimpervious synthetic resinous material and an overlayer of resilientcovering material.

4. An assembly as defined in claim 1 and in which said dimensionallystable layer consists essentially of a resilient covering materialadapted to be applied to a wall along the base thereof, whereby saidassembly forms a base strip.

5. An assembly as defined in claim 4 and including also a tack bar inspaced parallel relation to the base strip, and a flexible hingestructure bridging the space between the tack bar and base strip andflexibly connecting the same, said tack bar comprising an elongatedstrip of solid material carrying anchor formations for attaching theedge of a carpet.

6. An assembly as defined in claim 5 and in which said flexible hingestructureconsists essentially of an integral extension of said muslinlayer.

7. An assembly as defined in claim 1, and in which said dimensionallystable layer has the shape of a right dihedral angle with a filletbetween the sides of said dihedral angle, whereby said assembly isadapted to be applied to a wall at the base thereof and to the floorimmediately adjacent to said wall.

8. An assembly as defined in claim 7, wherein said dimensionally stablelayer is gradually reduced in thickness to a sharp edge along theportion adapted to be applied to the surface of a floor.

9. An assembly according to claim 7, and in which the side of saiddihedral angle adapted to be applied to the surface of a floor is cutback from its edge for only a portion of its thickness to form a shelfand a secondary edge, the leading edge of said side being adapted toabut a pad for a field covering and the secondary edge being adapted toabut a field of covering layer.

10. A generally fiat covering unit for covering a unit area of a surfaceof a building, comprising in combination a membrane of material thattends to swell when exposed to heat or dampness, pierced by a pluralityof narrow, mutualy spaced, variously directed slots to accommodatelateral movement of local membrane areas relative to each other, anupper muslin layer and a lower muslin layer impregnated and bonded tothe respective membrane faces with water impervious synthetic resinousmaterial, the memberane slots forming closed chambers unfillled by theresinous material, a tile of solid, slightly flexible, wear-resistantcovering material bonded to the upper muslin layer, the membrane, muslinlayers and tile all having essentially the same geometrical shape suchthat like units interfit to form a continuous covering. the membranedirectly overlying the lower muslin layer,

and at least the tile being offset diagonally with respect to themembrane and lower muslin layer to form laterally extending flangesproviding overlap between all adjoining edges of adjacent units.

References Cited UNITED STATES PATENTS JOHN T. GOOLKASIAN, PrimaryExaminer W. E. HOAG, Assistant Examiner U.S. C1. X.R.

